This invention relates to adaptive optics and, more particularly, to the application of wave front control technology to image sensing and recording.
To optically sense or record an image, an object scene is imaged onto a single sensor. This is typically accomplished by collecting light reflected from the object scene and focusing that light onto the sensor, such as a charged coupled device or complementary metal oxide semiconductor imaging array. The image sharpness, technically known as image resolution, and the field of view are limited by the number of pixels in the sensor. The common method for overcoming this drawback is to piece together a composite image from separate images of segments of the whole image taken by changing the position of the imaging system relative to the object scene, and recording the image at each position. Although this method will increase the total number of pixels used to image the object scene, it can be time consuming, prone to operator error, and can also lead to gaps and seams appearing in between the separate segments.
A common approach to obtaining a wider field of view is to use a wide angle lens to reduce the dimensions of an image to those compatible with the optical sensor. However, this degrades the resolution of objects within the field of view because the light reflected from the wider field of view is imaged onto the same number of pixels contained in the single imaging sensor.
In addition to the limit in resolution due to the limited number of pixels, a wide angle lens can introduce angle-dependent wave front errors, such as distortion, which is a variation in image magnification. The image may be in focus, but the scale is distorted at the extremities of the image. Other wave front errors such as field curvature, astigmatism, and coma can also increase with angulation and cause blurring of the image. Although, the optical aberrations caused by wave front errors can be minimized by designs well known to those skilled in the optical art, such modifications are complicated and expensive.
There is a need in the optical art for an image sensing and recording apparatus that provides high image resolution with a wide field of view, without seams and gaps, while also resolving the problems of wave front aberrations. The present invention addresses this need in the art.